The OutMultiEdgeView provides set-like operations on the edge-tuples
as well as edge attribute lookup. When called, it also provides
an EdgeDataView object which allows control of access to edge
attributes (but does not provide set-like operations).
Hence, G.edges[u,v]['color'] provides the value of the color
attribute for edge (u,v) while
for(u,v,c)inG.edges(data='color',default='red'):
iterates through all the edges yielding the color attribute
with default 'red' if no color attribute exists.

Edges are returned as tuples with optional data and keys
in the order (node, neighbor, key, data).

Parameters:

nbunch (single node, container, or all nodes (default= all nodes)) – The view will only report edges incident to these nodes.